Data storage cartridges may comprise rewritable media. Examples comprise magnetic tape media, various forms of optical disk media, magnetic disk media, various forms of optical tape media, and electronic memory media. In many instances, users desire to preserve data written to such rewritable media by protecting the data from being overwritten. The incorporated '846 and '803 patents allow protection of data written to data storage cartridges having rewritable media that is controlled by the data storage cartridges and that is tamper resistant. This allows the cartridges to be loaded in different data storage drives and the data is still protected. A write once flag is written to a lockable section of a cartridge memory, and the cartridge memory is locked. Additionally, a write once flag is written to a required data set of the rewritable media. Thus, write once flags are provided at both the locked section of the cartridge memory and the required data set of the rewritable media. The data storage drives are restricted by the write once flags and prevented from overwriting the protected data. Using the lockable section of the cartridge memory makes the protection tamper resistant. It is important that such cartridges (called WORM, write once-read many) are always protected.
A cartridge having such protection may not be available to a user at the time that the user finds it desirable to protect data against being overwritten. An example of protection of the data is discussed by the incorporated '810 patent which treats rewritable data storage media as write once by automatically advancing a write append limiter and operating the data storage drive to prevent changes to the data occurring before the write append limiter, and the incorporated '314 patent provides pointers at both the media and a cartridge memory to guard against tampering.